1. Field of the Invention
The present invention relates to a semiconductor memory field, and more particularly, to a memory module on which a plurality of semiconductor memory devices are mounted and an electronic component socket for coupling with the same.
2. Background of the Related Art
Currently, along with the rapid development of an information industry including the Internet and a semiconductor industry supporting the information industry, the computers gradually follow a trend toward high capacity and high performance. Accordingly, the semiconductor memory devices used in the computers also follow the trend toward high capacity and high performance. Like this, a plurality of semiconductor memory devices is mounted on a single memory module in order to enhance the memory capacity of the computers. Nowadays, the most widely used dual in-line memory module is configured such that signal pads are arranged in one row on one side of each of a first surface and a second surface of a printed circuit board to have a total of two rows.
Referring to FIG. 1, a conventional dual in-line memory module 101 includes a printed circuit board 102, a plurality of semiconductor memory devices 103 mounted on at least one of a first surface and a second surface of the printed circuit board, and a first signal pad array 104 and a second signal pad array 105 for electrically connecting the semiconductor memory devices 103 to an external system. Each of the first and second signal pad arrays 104 and 105 includes a plurality of signal pads which are spaced apart from each other at regular intervals.
Referring to FIG. 2, a conventional electronic component socket 201 is mounted to an external circuit board 301 and includes a first pin array 204 and a second pin array 205, each of which consists of a plurality of metal pins. The electronic component socket 201 is coupled with the dual in-line memory module 101 shown in FIG. 1. When the dual in-line memory module 101 is coupled to the electronic component socket 201, the signal pads thereof are electrically connected to the metal pins of the electronic component socket 201 so as to be electrically connected to first and second signal pad arrays 304 and 305 mounted on the external circuit board 301.
In order to further greatly improve performance and memory capacity of the conventional dual in-line memory module 101, it is required that the number of signal pads mounted on the first and second surfaces of the printed circuit board should increase. To this end, the pitch between the signal pads should be reduced or the size of the printed circuit board 102 should further greatly increase. However, there is a technical limitation in reducing the pitch between the signal pads. Thus, the size of the printed circuit board 102 should inevitably increase greatly in order to increase the number of signal pads, which leads to an increase in the size of the electronic component socket 201 coupled with the printed circuit board, and ultimately an increase in the size of a system board. This goes against the current trend toward the miniaturization and lightness of the system.
In addition, although it is desired to reduce the size of the memory module having the same performance as in the prior art, the size of the memory module cannot be reduced because of the first signal pad array 204 and the second signal pad array 205 mounted on the first surface and the second surface of the printed circuit board as shown in FIG. 3. This also goes against the current trend toward the miniature and lightness of the system.